FDC6324L - FAIRCHILD SEMICONDUCTOR

March 1999

FDC6324L

Integrated Load Switch

General Description Features

Absolute Operating Range TA = 25°C unless otherwise noted

Symbol Parameter FDC6324L Units

VIN Input Voltage Range 3 - 20 V

VON/OFF ON/OFF Voltage Range 1.5 - 8 V

I L Load Current @ VDROP=0.5V - Continuous (Note 1) 1.5 A

- Pulsed (Note 1 & 3) 2.5

PDMaximum Power Dissipation (Note 2a) 0.7 W

TJ,TSTG Operating and Storage Temperature Range -55 to 150 °C

ESD Electrostatic Discharge Rating MIL-STD-883D Human Body

Model (100pf/1500Ohm) 6kV

THERMAL CHARACTERISTICS

RθJA Thermal Resistance, Junction-to-Ambient (Note 2a) 180 °C/W

RθJC Thermal Resistance, Junction-to-Case (Note 2) 60 °C/W

FDC6324L Rev. D

These Integrated Load Switches are produced using Fairchild's

proprietary, high cell density, DMOS technology. This very high

density process is especially tailored to minimize on-state

resistance and provide superior switching performance. These

devices are particularly suited for low voltage high side load

switch application where low conduction loss and ease of driving

are needed.

VDROP=0.2V @ VIN=12V, IL=1A, VON/OFF=1.5 to 8V

VDROP=0.3V @ VIN=5V, IL=1A, VON/OFF=1.5 to 8V.

High density cell design for extremely low on-resistance.

VON/OFF Zener protection for ESD ruggedness. >6KV Human

Body Model.

SuperSOTTM-6 package design using copper lead frame for superior

thermal and electrical capabilities.

See Application Circuit

Vin,R1 Vout,C1

ON/OFF

R1,C1

Vout,C1

IN OUT

ON/OFF

EQUIVALENT CIRCUIT

VDROP

SuperSOT -6

pin 1

SOT-23 SuperSOTTM-8 SOIC-16

SO-8 SOT-223

SuperSOTTM-6

Electrical Characteristics (TA = 25°C unless otherwise noted)

Symbol Parameter Conditions Min Typ Max Units

OFF CHARACTERISTICS

IFL Forward Leakage Current VIN = 20 V, VON/OFF = 0 V 1µA

IRL Reverse Leakage Current VIN = -20 V, VON/OFF = 0 V -1 µA

ON CHARACTERISTICS (Note 3)

VIN Input Voltage 3 20 V

VON/OFF On/Off Voltage 1.5 8V

VDROP Conduction Voltage Drop @ 1A VIN = 10 V, VON/OFF = 3.3V0.135 0.2 V

VIN = 5 V, VON/OFF = 3.3 V0.215 0.3

ILLoad Current VDROP = 0.2 V, VIN = 10 V, VON/OFF = 3.3 V 1A

VDROP = 0.3 V, VIN = 5 V, VON/OFF = 3.3 V 1

Notes:

1. VIN=20V, VON/OFF=8V, VDROP=0.5V, TA=25oC

2. RθJA is the sum of the junction-to-case and case-to-ambient thermal resistance where the case thermal reference is defined as the solder mounting surface of the drain pins. RθJC is

guaranteed by design while RθCA is determined by the user's board design.

PD(t)=TJ

−TA

RθJA

(t)=TJ−TA

RθJC

+RθCA

(t)=ID

2(t)×RDS(ON)@TJ

Typical RθJA for single device operation using the board layouts shown below on FR-4 PCB in a still air environment:

a. 180oC/W when mounted on a 2oz minimum copper pad.

Scale 1 : 1 on letter size paper

3. Pulse Test: Pulse Width < 300µs, Duty Cycle < 2.0%

FDC6324L Rev. D

FDC6324L Rev.D

Typical Electrical Characteristics (TA = 25 OC unless otherwise noted )

Figure 1. VDROP Versus IL at VIN=12V.Figure 2. VDROP Versus IL at VIN=5.0V.

0 1 2 3 4

0.1

0.2

0.3

0.4

0.5

I ,(A)

V , (V)

DROP

T = 125°C

T = 25°C

V = 12V

V = 1.5 - 8V

PW =300us, D≤ 2%

ON/OFF

0 1 2 3 4

0.1

0.2

0.3

0.4

0.5

I (A)

V , (V)

DROP

V = 5V

V = 1.5 - 8V

PW =300us, D≤ 2%

ON/OFF

T = 25°C

T = 125°C

V (V)

DROP

1 2 3 4 5

0.2

0.4

0.6

0.8

V (V)

T = 125°C

T = 25°C

I = 1A

V = 1.5 - 8V

PW =300us, D≤ 2%

ON/OFF

Figure 3. VDROP Versus VIN at IL=1A.

012345

0.15

0.2

0.25

0.3

0.35

0.4

0.45

I , (A)

RDS(ON), (Ohm)

T = 125°C

T = 25°C

I = 1A

V = 5V

PW =300us, D≤ 2%

Figure 4. R(ON) Versus IL at VIN=5.0V.

1 2 3 4 5

0.2

0.4

0.6

0.8

V , (V)

R ,(Ohm)(ON)

T = 125°C

T = 25°C

I = 1A

V = 1.5 - 8V

PW =300us, D≤ 2%

ON/OFF

Figure 5. On Resistance Variation with

Input Voltage.

FDC6324L Rev. D

Figure 6. Switching Variation with R2 at

Vin=12V and R1=300KOhm.

Figure 7. Switching Variation with R2 at

Vin=5V and R1=300KOhm.

0 20 40 60 80 100

100

200

300

400

500

R2 (KOhm)

Time (us)

Vin = 3.3V

IL = 1A

Von/off = 5V

R1 = 300KOhm

Ci = 10uF

Co = 1uF

td(on)

td(off)

0 20 40 60 80 100

100

120

R2 (KOhm)

% of Current Overshoot

Vin = 12V

3.3V

IL = 1A

Von/off = 5V

R1 = 300KOhm

Ci = 10uF

Co = 1uF

0 20 40 60 80 100

100

200

300

400

500

R2 (KOhm)

Time (us)

td(on)

td(off)

Vin = 12V

IL = 1A

Von/off = 5V

R1 = 300KOhm

Ci = 10uF

Co = 1uF

0 20 40 60 80 100

100

200

300

400

500

R2 (KOhm)

Time (us)

Vin = 5V

IL = 1A

Von/off = 5V

R1 = 300KOhm

Ci = 10uF

Co = 1uF

td(on)

td(off)

Figure 8. Switching Variation with R2 at

Vin=3.3V and R1=300KOhm.Figure 9. % of Current Overshoot Variation

with Vin and R2.

0 20 40 60 80 100

400

800

1,200

1,600

2,000

R2 (KOhm)

Vdrop (mV)

IL = 1A

Von/off = 5V

R1 = 300KOhm

Ci = 10uF

Co = 1uF Vin = 3.3V

12V

Figure 10. Vdrop Variation with Vin and R2.

Typical Electrical Characteristics (TA = 25 OC unless otherwise noted )

Figure 11. Switching Waveforms.

10%

50%

90%

10%

90%

50%

VIN

VOUT

on off

d(off) fr

d(on)

t t

INVERTED

10%

PULSE WIDTH

FDC6324L Rev. D

0.1 0.2 0.5 1 2 5 10 20 30

0.01

0.03

0.1

0.3

V (V)

I , DRAIN CURRENT (A)

DROP

100ms

10ms

1ms

R(ON) LIMIT

100us

V = 12V

SINGLE PULSE

R = See Note 2a

T = 25°C

θJA

Figure 12. Safe Operating Area.

0.00001 0.0001 0.001 0.01 0.1 1 10 100 300

0.005

0.01

0.02

0.05

0.1

0.2

0.5

t , TIME (sec)

TRANSIENT THERMAL RESISTANCE

Single Pulse

D = 0.5

0.1

0.05

0.02

0.01

0.2

Duty Cycle, D = t / t1 2

R (t) = r(t) * R

R = See Note 2a

θJA

T - T = P * R (t)

θJA

P(pk)

t 1 t 2

r(t), NORMALIZED EFFECTIVE

Figure 13. Transient Thermal Response Curve.

Note: Thermal characterization performed on the conditions described in Note

2a. Transient thermal response will change depends on the circuit board

Typical Electrical Characteristics (TA = 25 OC unless otherwise noted )

FDC6324L Load Switch Application

General Description

This device is particularly suited for computer

peripheral switching applications where 20V

input and 1A output current capability are

needed. This load switch integrates a small

N-Channel Power MOSFET (Q1) which drives a

large P-Channel Power MOSFET (Q2) in one tiny

SuperSOTTM-6 package.

A load switch is usually configured for high side

switching so that the load can be isolated from

the active power source. A P-Channel Power

MOSFET, because it does not require its drive

voltage above the input voltage, is usually more

cost effective than using an N-Channel device in

this particular application. A large P-Channel

Power MOSFET minimizes voltage drop. By

using a small N-Channel device the driving

stage is simplified.

Component Values

R1 Typical 10k - 1MΩ

R2 Typical 0 - 10kΩ (optional)

C1 Typical 1000pF (optional)

Design Notes

R1 is needed to turn off Q2.

R2 can be used to soft start the switch in the case the output capacitance Co is small.

R2 ≤ should be at least 10 times smaller than R1 to guarantee Q1 turns on.

By using R1 and R2 a certain amount of current is lost from the input. This bias current loss is given by

the equation when the switch is ON. IBIAS_LOSS can be minimized by large R1.IBIAS _LOSS =Vin

R1+R2

R2 and CRSS of Q2 make ramp for slow turn on. If excessive overshoot current occurs due to fast turn on,

additional capacitance C1 can be added externally to slow down the turn on.

FDC6324L Rev. D

APPLICATION CIRCUIT

IN OUT

ON/OFF

LOADCo

TRADEMARKS

ACEx™

CoolFET™

CROSSVOLT™

E2CMOSTM

FACT™

FACT Quiet Series™

FAST®

FASTr™

GTO™

HiSeC™

The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is

not intended to be an exhaustive list of all such trademarks.

LIFE SUPPORT POLICY

FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT

DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROV AL OF FAIRCHILD SEMICONDUCTOR CORPORA TION.

As used herein:

1. Life support devices or systems are devices or

systems which, (a) are intended for surgical implant into

the body, or (b) support or sustain life, or (c) whose

failure to perform when properly used in accordance

with instructions for use provided in the labeling, can be

reasonably expected to result in significant injury to the

user.

2. A critical component is any component of a life

support device or system whose failure to perform can

be reasonably expected to cause the failure of the life

support device or system, or to affect its safety or

effectiveness.

PRODUCT ST A TUS DEFINITIONS

Definition of Terms

Datasheet Identification Product Status Definition

Advance Information

Preliminary

No Identification Needed

Obsolete

This datasheet contains the design specifications for

product development. Specifications may change in

any manner without notice.

This datasheet contains preliminary data, and

supplementary data will be published at a later date.

Fairchild Semiconductor reserves the right to make

changes at any time without notice in order to improve

design.

This datasheet contains final specifications. Fairchild

Semiconductor reserves the right to make changes at

any time without notice in order to improve design.

This datasheet contains specifications on a product

that has been discontinued by Fairchild semiconductor.

The datasheet is printed for reference information only.

Formative or

In Design

First Production

Full Production

Not In Production

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER

NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD

DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICA TION OR USE OF ANY PRODUCT

OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS P ATENT

RIGHTS, NOR THE RIGHTS OF OTHERS.

TinyLogic™

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ISOPLANAR™

MICROWIRE™

POP™

PowerTrench™

QFET™

QS™

Quiet Series™

SuperSOT™-3

SuperSOT™-6

SuperSOT™-8